The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Automatic transmissions in vehicles often contain planetary gear sets to transmit one or more forward and reverse gear speed ratios between an engine and at least one drive axle. These planetary gear sets experience significant stress at high levels of RPM operation of the automatic transmission. Therefore, it is desirable to have adequate levels of lubrication provided to the bearing elements of the planetary gear sets. Typically this is accomplished by using a pressurized lubrication system that provides pressurized lubrication oil to the bearing elements. While effective, these pressurized systems can be subject to leakage and can be difficult to assemble due to orientation requirements in order to maintain a pressurized oil circuit to feed the bearings. An alternate method of providing adequate lubrication to the bearing elements is a non-pressurized lubrication system. While effective, to provide adequate lubrication these systems require that the transmission pump provide a greater volume of oil relative to pressurized systems. Therefore, the transmission pump in a non-pressurized system must have an increase in performance or require a larger pump. However, increases in pump performance requirements may reduce the durability of existing pumps. Larger pumps may present packaging issues and may reduce fuel efficiency. Accordingly, there is a need for a pressurized lubrication system for a planetary gear set that minimizes leakage, provides lubrication to the bearing elements in any condition, and does not compromise the ease of assembly of the planetary gear set.